Compulsive habits in restless legs syndrome patients under dopaminergic treatment

Since the introduction of levodopa therapy and dopaminergic replacement therapy to abate symptoms of idiopathic Parkinson's disease, repetitive compulsive behaviors have been reported and are now considered to be drug-related response complications. As dopamine (DA) agonists are the licensed treatment in Restless Legs Syndrome (RLS), a survey was conducted to determine the extent to which patients with RLS present compulsive behaviors. The aim of this study was to investigate the relationship between DA agonists and the occurrence of motor or behavioral compulsions, stress, depression, and sleep disturbance in RLS patients. A questionnaire was mailed three times, at four-month intervals over a period of 8 months to all patients of the Quebec Memory and Motor Skills Disorders Clinic diagnosed with RLS. In addition to recording all medication information for RLS treatment, patients were assessed on the International Restless Legs Syndrome Study Group Rating Scale (IRLS), the Beck Depression Inventory-II (BDI-II), the Sleep Scale from the Medical Outcomes Study (MOS) and on a visual analog scale for current level of stress. A section pertaining to hobby, mania, and compulsion was also included. Analyses are based on 97 out of 151 patients (64.2%) with RLS who returned the three questionnaires. Twelve patients (12.4%) on stable DA agonist therapy (average dose 0.52+/-0.59 mg Pramipexole equivalent) developed a new compulsive behavioral repertoire. Eating (3 women, 1 man), buying food or clothes (2 women, 1 man), trichotillomania (1 woman, 1 man), and gambling (1man) were among the compulsions developed under DA treatment. In addition, two women presented new tic-like phenomena. In contrast to the RLS patients without compulsive behaviors (53 treated with DA agonist; 32 untreated), those with compulsive habits reported experiencing more stress, depression and sleep problems. Patients with RLS with mood and stress states may be at greater risk of developing compulsive behaviors while receiving standard dosage DA agonist treatment. These behaviors are clearly linked to short-term satisfaction and underline the role of dopaminergic mesolimbic stimulation in the reinforcement process of rewarding behavioral sequences.